An ejection head unit is attachable to an inhaler for ejecting a medicine to cause a user to inhale the medicine and has a plurality of ejection heads having an element generating energy for ejecting the medicine, and a plurality of ejection nozzles through which the medicine is ejected by the element. An inhaler for ejecting a medicine to allow inhalation thereof by a user has an air flow path guiding a medicine that is inhaled accompanying inspiration by the user to a suction port, an ejection head unit having a plurality of ejection heads including an element generating energy for ejecting the medicine and a plurality of ejection nozzles through which the medicine is ejected by the element, and a positioning unit for positioning a single ejection head among the plurality of ejection heads at an opening provided in one portion of the air flow path.